South Asian Journal of Research in Microbiology

Antimicrobial Susceptibility and Biofilm-Forming Ability of Airborne Bacteria Isolated from Selected Livestock Farms and Abattoirs in Port Harcourt, Nigeria

Owhonka Aleruchi — 2026-10-01

Background: Airborne microbial contamination in livestock farms and abattoirs poses significant public health, animal welfare, and food safety risks because of high animal density, inadequate ventilation, and processing activities that generate bioaerosols.

Materials and Methods: This study assessed the distribution, diversity, antibiotic susceptibility, and biofilm-forming potential of airborne microorganisms in six livestock-related environments in Port Harcourt, Nigeria: Piggery Farm, Goat Farm, Cattle Farm, Rumuokoro Abattoir, Eagle Island Abattoir, and Tech Farm Abattoir. Air samples were collected by passive sedimentation using exposed Nutrient Agar, MacConkey Agar, and Sabouraud Dextrose Agar plates placed in areas of high animal activity, waste disposal, and slaughter-processing operations for 10 minutes. The plates were incubated at 37°C for 24–72 hours. Bacterial isolates were identified using colonial morphology, Gram staining, and standard biochemical tests, while fungal isolates were identified based on their macroscopic and microscopic characteristics. Antibiotic susceptibility was determined using the Kirby–Bauer disc diffusion method, and microbial load was expressed as colony-forming units per minute per square metre (CFU/min·m²).

Results: Rumuokoro Abattoir recorded the highest microbial load, with total heterotrophic bacterial count, total coliform count, and total fungal count of 36.38 ± 15.91, 38.60 ± 18.24, and 5.10 ± 0.28 CFU/min·m², respectively. A total of 24 bacterial isolates belonging to nine genera were identified, comprising Staphylococcus spp., Bacillus spp., Lederbergia sp., Micrococcus sp., Serratia spp., Arsenophonus sp., Cronobacter sp., Klebsiella spp., and Citrobacter spp. Staphylococcus spp. showed the highest occurrence (29.2%), followed by Bacillus spp. (20.8%). Five fungal taxa were recovered: Penicillium sp., Mucor sp., Aspergillus niger, Trichophyton sp., and Fusarium sp. Antibiotic susceptibility testing showed that most Bacillus spp. and Staphylococcus spp. were resistant to rifampicin, ceftazidime, azithromycin, and cefuroxime, with only limited susceptibility to gentamicin and levofloxacin. Among the Gram-negative isolates, Serratia spp. and Citrobacter spp. were resistant to all antibiotics tested, whereas Klebsiella spp. and Cronobacter spp. exhibited susceptibility to selected antibiotics with some intermediate responses. Biofilm production was detected in Klebsiella spp., Citrobacter spp., and Bacillus spp.

Conclusion: The livestock farms and abattoirs in the study areas harbours diverse airborne microorganisms, including antibiotic-resistant and biofilm-forming bacterial species, with abattoirs exhibiting the highest microbial contamination.

Influence of Chemical Preservatives on Quality Attributes of Kunu-zaki-a Nigerian Traditional Fermented Cereal Beverage

Isaac Ayanniran Adesokan — 2026-10-15

Kunu-zaki is a traditional fermented cereal beverage valued for its accessibility but susceptible to microbial spoilage during storage. This study examined the effects of sodium benzoate (E211), potassium sorbate (E202) and their combination on the physicochemical, microbiological and sensory characteristics of kunu-zaki. Laboratory-prepared beverage samples were allocated to four treatments: sodium benzoate at 0.1% (A), potassium sorbate at 0.1% (B), a combination of both preservatives at 0.05% each (C) and an untreated control (D). Samples were assessed on days 0, 2 and 4 for pH, proximate composition and microbial counts; sensory characteristics were evaluated by 20 panellists using a five-point hedonic scale. The control pH declined from 5.8 to 3.3 during storage, whereas the corresponding day-4 pH values for treatments A, B and C were 5.2, 5.0 and 5.3, respectively. The day-4 total viable counts were 1.0 × 10⁶, 1.0 × 10⁶, 5.0 × 10⁵ and 8.0 × 10⁶ CFU/mL for A, B, C and D, respectively. No yeast/mould count was recorded for treatment C on day 4, whereas the control had a count of 5.0 × 10⁷ CFU/mL. Overall sensory acceptability scores were 3.4, 4.0, 3.8 and 1.6 for samples A–D, respectively. These findings suggest that the preservatives influenced selected quality indicators during four days of storage, although remaining microbial counts preclude conclusions about product safety.

An Alternative Approach to Extraction of Enzymes from Saccharomyces cerevisiae Using Snail Slime and Hydraulic Pressure

Joy Uchechukwu Ezeonyilimba — 2026-10-17

The need for environmentally sustainable enzyme extraction methods has increased due to the growing demand for industrial bioprocesses. In this study, slime from Achatina achatina combined with syringe-needle hydraulic pressure was used to lyse Saccharomyces cerevisiae cells and recover a crude intracellular enzyme extract. Cells from a stock of a highly ethanol-tolerant strain of Saccharomyces cerevisiae isolated from palm wine were cultured on modified Potato Dextrose Agar (PDA) supplemented with 0.5% potassium phosphate (K₂HPO₄) and incubated in a candle jar for 3 days. A standardised yeast suspension was prepared from the resulting colonies. Equal volumes of Saccharomyces cerevisiae suspension and snail slime (1:1 ratio) were mixed and left to stand for 1 hour. The mixture was repeatedly homogenized by hydraulic pressure through repeated syringe-needle (340 µm) passage for three rounds. The lysed cell suspension was filtered through a 0.45 µm membrane filter to obtain a crude enzyme extract. The extract was evaluated for its ethanol production potential using glucose solutions at different concentrations (1%, 2.5%, 5%, 7.5%, and 10% v/v). The results showed that no ethanol was detected at 1% glucose, while ethanol yield increased progressively with increasing glucose concentration, from 0.27% v/v at 2.5% glucose concentration to 0.37% v/v at 10% glucose concentration. The absence of ethanol at 1% glucose likely reflected insufficient carbon substrate, whereas higher glucose levels supported measurable enzymatic activity. These findings indicated that snail slime-assisted lysis combined with hydraulic pressure effectively disrupted yeast cells and yielded active enzyme extracts capable of ethanol production. This approach offers a simple, eco-friendly, and low-cost alternative to conventional crude enzyme extraction techniques and may have potential applications in industrial biotechnology and cell-free ethanol production systems.

Phenotypic Drug Susceptibility Patterns of Mycobacterium tuberculosis Isolates to First-Line Anti-Tuberculosis Drugs in South-Western Nigeria

R. Warrens — 2026-10-23

Drug-resistant tuberculosis (TB) undermines global TB control efforts, yet comprehensive phenotypic drug susceptibility data from South-Western Nigeria remain limited. Understanding local resistance patterns is essential for optimising treatment regimens and informing programmatic responses. This study aimed to determine the phenotypic susceptibility patterns of culture-confirmed Mycobacterium tuberculosis isolates to first-line anti-tuberculosis drugs among patients in South-Western Nigeria. Seventy-four GeneXpert MTB/RIF-positive sputum specimens from patients attending health facilities in Osun, Oyo, and Lagos States underwent mycobacterial culture on Löwenstein-Jensen medium. Culture-confirmed M. tuberculosis isolates were subjected to phenotypic drug susceptibility testing against rifampicin, isoniazid, and ethambutol using the proportion method. Of 74 GeneXpert-positive specimens cultured, 51 (68.9%) yielded M. tuberculosis. Among these 51 isolates, 36 (70.6%) demonstrated resistance to at least one first-line drug. Rifampicin resistance was detected in 27 isolates (52.9%), isoniazid resistance in 18 (35.3%), and ethambutol resistance in 13 (25.5%). Fifteen isolates (29.4%) met criteria for multidrug-resistant TB (MDR-TB), defined as combined rifampicin and isoniazid resistance. Analysis of the geographical distribution revealed that 74.1% of rifampicin-resistant, 77.8% of isoniazid-resistant, and 84.6% of ethambutol-resistant isolates originated from Osun State. Substantial resistance to first-line anti-tuberculosis drugs, particularly rifampicin, was detected among culture-confirmed M. tuberculosis isolates in South-Western Nigeria. The high prevalence of drug resistance and MDR-TB highlights the need for routine culture and drug susceptibility testing to guide individualized treatment and prevent treatment failure.

Occurrence and Antimicrobial Susceptibility of Staphylococcus aureus on High-Touch Hospital Surfaces in a Tertiary Healthcare Facility in Yenagoa, Nigeria

Ebidor Lawani-Luwaji — 2026-10-26

Background: High-touch surfaces in healthcare facilities may serve as reservoirs for Staphylococcus aureus and contribute to the persistence and transmission of antimicrobial-resistant organisms within hospital environments.

Aim: This study determined the occurrence and antimicrobial susceptibility patterns of S. aureus isolated from selected high-touch surfaces at a tertiary healthcare facility in Yenagoa, Nigeria.

Methods: Sixty environmental samples from high-touch surfaces were collected from outpatient and public health units of the health facility. Staphylococcus aureus was isolated and identified using standard microbiological methods, and antimicrobial susceptibility was tested by disc diffusion according to CLSI criteria.

Results: Of the 60 high-touch surface samples tested, 53 (88.3%) were positive for S. aureus. Among the 53 S. aureus isolates, resistance was highest against erythromycin (32.1%), followed by gentamicin (30.2%), azithromycin (22.6%), and levofloxacin (20.8%). Resistance to streptomycin was 11.3%, whereas amoxicillin, ciprofloxacin, and cefuroxime each showed 7.5% resistance. Rifampicin had the lowest resistance rate (1.9%).

Conclusion: S. aureus was highly prevalent on the sampled high-touch surfaces, indicating contamination within the hospital environment. Although most isolates were susceptible to the antimicrobial agents tested, resistance varied, particularly to erythromycin and gentamicin. These findings highlight the importance of effective environmental hygiene and continued surveillance of S. aureus and antimicrobial resistance on frequently touched surfaces in healthcare facilities.

Culture-based Characterization of Faecal Bacterial Isolates Following a Two-week Green Tea Intervention among Rivers State University Students, Port Harcourt, Nigeria

Vivian Nkemkanma Agi — 2026-10-26

Green tea, produced from the leaves of Camellia sinensis, is consumed worldwide because of its reported antioxidant, anti-inflammatory, antimicrobial, and health-promoting properties. Emerging evidence suggests that dietary components, including green tea polyphenols, may influence the composition and activity of intestinal microorganisms. However, information on the culture-based bacterial profile of stool samples following green tea consumption among healthy Nigerian adults remains limited. This study aimed to evaluate changes in the culture-based profile of faecal bacterial isolates during a two-week green tea intervention among Rivers State University students, Port Harcourt, Nigeria. A prospective repeated-measures intervention study was conducted among 30 apparently healthy Rivers State University students residing in the university hostels. Each participant provided stool samples at three time points: baseline (before green tea consumption), after one week, and after two weeks of daily green tea intake, resulting in a total of 90 stool specimens. Stool samples were cultured on selective and differential bacteriological media, and bacterial isolates were identified using standard microbiological procedures, including colony morphology, Gram staining, and conventional biochemical tests. Data were analysed using descriptive statistics and presented as frequencies and percentages. The bacterial taxa recovered during the study included Escherichia coli, Staphylococcus aureus, Klebsiella spp., Enterobacter spp., and Salmonella spp. The frequency of recovery of Escherichia coli increased from 16.7% at baseline to 23.3% after one week and 30.0% after two weeks of the green tea intervention. Similar trends were observed for some of the other bacterial isolates. Conversely, the proportion of stool samples with no detectable bacterial growth on the culture media used decreased from 60.0% at baseline to 43.3% after one week and remained at 43.3% after two weeks of the intervention. The findings of this study suggest that a two-week green tea intervention was associated with changes in the frequency of recovery of selected cultivable faecal bacterial isolates among Rivers State University students. However, as the study relied solely on conventional culture-based methods, these findings should not be interpreted as evidence of comprehensive alterations in gut microbiota composition or of adverse effects on gut health. Furthermore, the relatively small sample size and short duration of the intervention may limit the generalisability of the findings. Future studies involving larger and more diverse populations, longer intervention periods, and molecular microbiome techniques are recommended to provide a more comprehensive understanding of the relationship between green tea consumption and the intestinal microbial community.

Optimization of Pectinase Production by a Potent Fungal Isolate Obtained from Spoiled Fresh Produce

Justina Kenechukwu Anozie — 2026-10-27

Fungal pectinases are extracellular enzymes associated with the degradation of pectic substances in plant tissues and have applications in biotechnological processing. This study assessed the pectinolytic activity of fungi isolated from spoiled fresh produce and examined the effects of assay temperature, pH and reaction time on a selected crude enzyme preparation. Five fungal groups—Aspergillus, Penicillium, Fusarium, Rhizopus and Alternaria—were screened on pectin-containing medium using hydrolysis-zone diameter. The most active isolate was subsequently identified as Aspergillus niger. Screening and quantitative assays were performed in triplicate, and differences between treatments were assessed using one-way analysis of variance and Tukey's test. Aspergillus niger produced the largest hydrolysis zone (6.35 ± 0.15 mm), exceeding those of the other four groups (p < 0.05). Its measured pectinase activity increased from 2.23 ± 0.10 U/mL at 10°C to 9.86 ± 0.25 U/mL at 40°C, before decreasing at 50°C. The highest activity in the pH experiment was 10.04 ± 0.20 U/mL at pH 7. Activity in the reaction-time experiment reached 18.74 ± 0.16 U/mL at 20 min and did not improve significantly at 25 min (p = 0.653). Overall effects of temperature, pH and reaction time were significant (p < 0.001). These findings identify assay-specific conditions associated with the highest observed crude pectinase activity within the evaluated ranges, without establishing optimum enzyme-production conditions during fungal cultivation.

Antibacterial Activity of Honey against Escherichia coli, Staphylococcus aureus and Bacillus Species

V. NagaPranavi — 2026-10-28

Honey possesses antibacterial properties associated with its high sugar concentration, acidic pH, hydrogen peroxide production and bioactive phytochemicals. This study examined the growth-inhibitory activity of honey against selected bacterial isolates. Microorganisms were isolated from sewage water (Escherichia coli), human skin (Staphylococcus aureus) and soil (Bacillus species). The methodology involved preparation of selective media, serial dilution, cultivation by the pour-plate method and identification based on cultural characteristics and biochemical analysis. Antibacterial responses were presented as zones of inhibition. The figure depicting the experimental observations reported inhibition zones of 20 mm for E. coli, 12 mm for S. aureus and 8 mm for Bacillus. Thus, E. coli showed the largest inhibition zone among the three organisms under the reported conditions. The observed responses are consistent with the antibacterial potential of honey, although the contributions of its individual chemical and physical properties were not separately established in this study. Inhibition-zone measurements indicate growth inhibition under the assay conditions but do not independently demonstrate bactericidal activity or clinical efficacy. Moreover, inhibition of Bacillus growth should not be interpreted as evidence of endospore destruction. The findings provide preliminary laboratory evidence of variability in bacterial responses to honey. Additional controlled investigation would be necessary to establish the reproducibility of the observations and assess their relevance to potential antimicrobial applications.

Biofilm Forming Potential and Extended Spectrum Beta Lactamase of Bacterial Isolates from Hospital Wards in Abia State

Ebubechi Uloma Okey-kalu — 2026-10-29

Biofilm-forming potential and extended-spectrum beta-lactamase production in hospital wards are of public health concern. The ability of bacteria to proliferate on surfaces may pose a threat to human lives. This study evaluated the biofilm-forming potential and extended-spectrum beta-lactamase production of bacterial isolates from hospital wards in Abia State. Samples from selected hospital wards were collected and cultured on blood agar, MacConkey agar and mannitol salt agar. Pure cultures were obtained by subculturing the isolates on nutrient agar. Appropriate biochemical tests were carried out to identify the organisms. The biofilm-forming potential of the different bacterial isolates was assessed using the Congo red agar method. Extended-spectrum beta-lactamase (ESBL) assays were performed on the Gram-negative bacterial isolates using the double-disc diffusion test. The most common bacterial isolate was Staphylococcus aureus, 206 (52.82%) followed by coagulase-negative staphylococci, 99 (25.38%) while the least common bacterial isolate was Streptococcus spp., 4 (1.03%). Staphylococcus aureus had the highest biofilm-forming potential, 130 (63.11%) while Streptococcus spp. had the least biofilm-forming potential, 1 (25%). Thirty (40%) Escherichia coli isolates and 2 (33.33%) Klebsiella pneumoniae isolates were ESBL-positive. This study demonstrated biofilm formation and extended-spectrum beta-lactamase production among the bacterial isolates.

Antibacterial Potential of Extracts from Allium sativum (Garlic), Allium tuberosum (Ganda), Allium fistulosum (Sebilyeno), Allium ampeloprasum (Leeks) and Allium cepa (Onion)

Diana Juan — 2026-10-30

Antimicrobial resistance has encouraged investigation of plant-derived compounds with potential antibacterial activity. This study examined the antibacterial potential of leaf extracts from Allium sativum (Garlic), A. tuberosum (Ganda), A. fistulosum (Sebilyeno), A. ampeloprasum (Leeks), and A. cepa (Onion) to address the escalating global health issue of antibiotic resistance. Over a 12-month period, the research aimed to evaluate these extracts’ phytochemical composition – specifically alkaloids, flavonoids, phenolic compounds, saponins, and tannins – and assess their antibacterial effectiveness against Escherichia coli and Staphylococcus aureus. By comparing the bacterial growth inhibition potential of each plant extract, the study aimed to determine whether their inhibitory effects differed significantly from those of a commercially available antibiotic. Contrary to expectations based on traditional uses and reported bioactive compounds, the study found that none of the tested Allium extracts exhibited a zone of inhibition against either Staphylococcus aureus or Escherichia coli in the assays performed. While phytochemical screening confirmed the presence of flavonoids, phenolic compounds, saponins, and tannins in varying concentrations, these compounds, at the concentrations tested and under the tested conditions, did not demonstrate detectable antibacterial activity. These results suggest that while these Allium species possess various phytochemicals, the specific extraction methods, concentrations, and assay conditions used in this study did not yield antibacterial effects against the tested bacterial strains. This study highlights the need for further research to optimise extraction techniques, explore synergistic effects between compounds, and investigate different bacterial strains to fully understand the potential antibacterial properties of these Allium species.

Antibiotic Susceptibility, Molecular Characterization and Detection of TSST Gene in S. aureus and LT Gene in E. coli Isolates from Public Toilets in Port Harcourt, Nigeria

O. Ejims-Enwukwe — 2026-10-30

Public toilet environments may harbour bacteria with antimicrobial resistance and virulence-associated genes. This study assessed the antibiotic susceptibility and molecular characteristics of Staphylococcus aureus and Escherichia coli recovered from toilet bowls and seats in public facilities in Port Harcourt, Nigeria. Isolates were identified using cultural and biochemical characteristics, and antibiotic susceptibility was assessed by disc diffusion on Mueller–Hinton agar. Molecular investigations included 16S rRNA and gyrA amplification and screening for toxic shock syndrome toxin (TSST) and heat-labile toxin (LT) genes. Staphylococcus aureus isolates were fully susceptible to ciprofloxacin and gentamicin, while susceptibility to levofloxacin and azithromycin was 96% and 93%, respectively. Resistance to ceftazidime and cefuroxime was 75% and 71%, respectively. Escherichia coli exhibited complete susceptibility to ciprofloxacin, ofloxacin and peflacine, but resistance to ceftazidime, cefuroxime and ceporex was 100%, approximately 94% and approximately 88%, respectively. Multiple antibiotic resistance indices were generally higher among Escherichia coli isolates. Molecular characterisation involved six Staphylococcus aureus and four Escherichia coli isolates, with gyrA and 16S rRNA amplification reported. All six tested Staphylococcus aureus isolates yielded TSST-associated amplicons, and all four Escherichia coli isolates yielded LT-associated amplicons. These findings document varied antibiotic susceptibility and the presence of selected virulence-associated gene markers in bacteria recovered from the sampled public toilets. Regular environmental microbiological surveillance and appropriate sanitation practices are warranted.

Formulation and Evaluation of Biopesticides Derived from Local Biological Resources for the Sustainable Post-harvest Preservation of Fresh Fruits and Vegetables

Kouamé N´zebo Desiré — 2026-10-31

Background: Post-harvest deterioration of fruits and vegetables poses a major challenge for food preservation, particularly in Côte d’Ivoire. The development of biological solutions using local biological resources represents a promising approach to limiting these losses.

Aims: The overall objective of this study was to formulate and evaluate biopesticides designed to ensure the long-term preservation of fresh fruit and vegetables after harvest.

The overall objective of this study was to formulate and evaluate biopesticides to explore their potential for extending the shelf life of fresh fruit and vegetables after harvest.

Methods: Three formulations were investigated: BS, based on metabolites produced by Bacillus subtilis in a filtrate of ageing papaya pulp; BS/T, combining these metabolites with tomato filtrate; and PS/T, prepared from papaya seeds and tomato filtrate. The estimated production of lipopeptides was monitored during fermentation. The antifungal activity, pH and sedimentation of the formulations were assessed over a four-week period at 4 °C and at approximately 33 °C. Their preservative potential was also examined in bananas, tomatoes, aubergines, mangoes, papayas and cucumbers by monitoring changes in weight and spoilage scores.

Results: The results showed antifungal activity for all three formulations, to varying degrees. BS/T exhibited lower activity than BS under the conditions assessed, while PS/T stood out for producing the largest inhibition zone at approximately 33 °C (27.00 ± 0.58 mm in the first week) and lower sedimentation after four weeks at this temperature. The effects on the storage life of fruit and vegetables varied between products, with no consistent efficacy across all formulations. All three formulations exhibited antifungal activity of varying intensity. The PS/T formulation showed the largest zone of inhibition during the first week (27.00 ± 0.58 mm; mean ± standard deviation, n = 3). During stability testing at 4 °C and approximately 33 °C, this formulation exhibited less sedimentation after four weeks at approximately 33 °C, while the other formulations showed better stability at 4 °C. Preservation tests, conducted over 14 days on six types of fruits and vegetables, revealed varying effects depending on the produce and the formulations.

Conclusion: These results indicate that the PS/T formulation showed the most promising antifungal potential under the conditions studied, but further trials under real-world conditions are needed to confirm its post-harvest efficacy. The PS/T formulation shows promising antifungal potential and good stability at approximately 33 °C. However, the variable effects observed on different fruits and vegetables do not allow for a conclusion regarding uniform efficacy for postharvest storage. Additional trials under real-world conditions are needed to confirm its potential for application.

Seroprevalence of Herpes Simplex Virus Type-2 (HSV-2) Infection among Pregnant Women Attending Antenatal Care at Plateau State Specialist Hospital, Jos, Nigeria

Jonah Yisa — 2026-10-31

Background and Aim: Herpes simplex virus type 2 is a globally significant cause of genital herpes and persists lifelong, with intermittent subclinical shedding driving ongoing transmission. During pregnancy, the infection is of major concern because of mother-to-child transmission, which can result in neonatal herpes associated with severe morbidity and mortality, as well as a heightened risk of HIV acquisition. The aim of this study was to determine the seroprevalence of HSV-2 infection among pregnant women attending the antenatal clinic at Plateau State Specialist Hospital, Jos.

Place of Study: The study was conducted at Plateau State Specialist Hospital, Jos, Plateau State, Nigeria.

Methodology: This was a cross-sectional, hospital-based study conducted among 94 pregnant women who were screened for herpes simplex virus type 2 (HSV-2) using enzyme-linked immunosorbent assay (ELISA) techniques. Sociodemographic characteristics, risk factors and clinical characteristics were analysed in relation to HSV-2 test outcomes. Associations were determined using the chi-square test, with statistical significance set at p < 0.05.

Results: Of 94 pregnant women screened at Plateau State Specialist Hospital, Jos, 28 (29.8%) were positive for HSV-2 IgM antibodies. None of the sociodemographic variables (age, occupation, marital status and level of education), sexual and obstetric risk factors (number of sexual partners, condom use, sex during pregnancy and trimester), or clinical manifestations, including fever, vaginal discharge, genital itching, genital blisters/ulcers and pain in the thighs, knees and buttocks, was significantly associated with HSV-2 IgM positivity (p > 0.05). Pain during urination was the only clinical variable significantly associated with HSV-2 IgM positivity (p = 0.032).

Conclusion: HSV-2 IgM positivity was observed in 29.8% of the pregnant women studied, with variations across sociodemographic, sexual, obstetric and clinical characteristics. Pain during urination was significantly associated with seropositivity.

Antimicrobial Effect of Curcuma longa and Zingiber officinale on Bacteria Isolated from Domestic Dogs in Port Harcourt, Nigeria

Wobareri Chuku — 2026-11-03

Background: Antimicrobial resistance in canine microbiota, influenced by antibiotic use in veterinary medicine and environmental exposure, poses a public health risk. Medicinal plants offer a potential multi-targeted approach to addressing antimicrobial resistance.

Materials and Methods: This study assessed the antimicrobial effects of Curcuma longa and Zingiber officinale on bacterial isolates from domestic dogs in Port Harcourt, Nigeria. Sterile swabs were used to collect samples from the mouth, skin, ear and anus of domestic dogs. Samples were cultured on nutrient agar, mannitol salt agar, eosin methylene blue agar and MacConkey agar. Bacterial isolates were identified by colonial morphology, Gram staining and biochemical tests. Antibiotic susceptibility was assessed using the Kirby–Bauer disc diffusion method. The antimicrobial effects of the plant extracts were evaluated using the disc diffusion method.

Results: A total of 14 bacterial isolates belonging to 10 genera were identified: Klebsiella spp., Proteus spp., Enterobacter spp., Escherichia spp., Kluyvera spp., Providencia spp., Salmonella spp., Bacillus spp., Staphylococcus spp. and Micrococcus spp. Antibiotic susceptibility testing showed that Salmonella spp. isolates exhibited 100% resistance to Ceporex, ceftriaxone, streptomycin, cefuroxime, Augmentin and ceftazidime, while other isolates showed varying degrees of resistance and susceptibility to the antibiotics tested. In the plant-extract susceptibility test, 75% of the tested isolates were inhibited by ethanolic turmeric extracts, compared with 50% by ethanolic ginger extracts.

Conclusion: Domestic dogs harbour microorganisms that display resistance to conventional antibiotics and susceptibility to ethanolic extracts of turmeric and ginger. These plants could serve as additives for the production of dog feed or dog-cleaning agents.

Phenotypic Characterization, Virulence-Associated Traits and Antibiotic Susceptibility Profiles of Bacterial Isolates from High Vaginal Swabs in Port Harcourt, Nigeria

EYO, Esther Joseph-Justine — 2026-11-10

This study investigated the occurrence of culturable microorganisms, phenotypic virulence-associated traits and antibiotic susceptibility patterns of bacterial isolates recovered from high vaginal swabs (HVS) and unused sanitary pads in Port Harcourt, Rivers State, Nigeria. A total of 149 HVS specimens were obtained from two health facilities, comprising 75 specimens from Mile 4 Primary Healthcare Centre, Rumuokwurushi, and 74 from Orogbum Primary Healthcare Centre. In addition, 216 unused sanitary pads were collected from selected markets and pharmacies. Samples were analysed using standard microbiological culture and identification procedures. Bacterial isolates were assessed for selected phenotypic traits, including haemolysis, biofilm formation, motility, enzyme production and other organism-associated characteristics. Antibiotic susceptibility testing was also performed on selected bacterial isolates. Among the HVS specimens, 74 (49.7%) yielded bacterial growth, 10 (6.7%) yielded yeast growth, and 6 (4.0%) showed mixed bacterial and yeast growth, while 59 (39.6%) showed no microbial growth. HVS bacterial isolates exhibited varying frequencies of haemolysis, biofilm formation, motility and enzyme production. Bacteria recovered from unused sanitary pads also displayed selected phenotypic traits, with variations among the identified bacterial groups. Antibiotic susceptibility results for staphylococcal isolates indicated high resistance to cefotaxime, cefuroxime and ampiclox (100% each), while susceptibility was highest to gentamicin (93.3%) and levofloxacin (86.7%). Resistance was also reported among Gram-negative isolates, with interpretation restricted to the displayed organism-specific observations and isolate numbers. The findings demonstrate the occurrence of culturable microorganisms and phenotypic virulence-associated traits in the investigated samples, alongside concerning resistance patterns among some bacterial isolates. Further studies using molecular identification, standardised susceptibility testing and larger sample sizes are required to confirm organism identity and establish more robust virulence and antimicrobial resistance profiles.

Bioremediation of Artisanal Refinery Contaminated Soils Enhanced with Biostimulant

D. Oluwabunmi Olafusi — 2026-11-12

Background: Artisanal petroleum refining contaminates soils and may constrain their ecological recovery.

Aim: This study assessed the effectiveness of composted agricultural waste and NPK fertiliser in reducing hydrocarbon contamination in soils affected by artisanal refining activities in Obi-Ayagha community, Delta State, Nigeria.

Study Design: An experimental study was conducted to evaluate the effects of organic and inorganic amendments on the remediation of hydrocarbon-contaminated soils, using untreated soil as the control.

Place and Duration of Study: The study was conducted in Obi Ayagha community, Ughelli South Local Government Area, Delta State, Nigeria, over a period of nine weeks (63 days).

Methodology: Contaminated soil samples were treated with composted agricultural waste and NPK fertiliser at different amendment levels, while untreated soil served as the control. Soil pH, moisture content, electrical conductivity (EC), nitrate concentration, nutrient composition, and microbial populations were monitored at three-week intervals. Total petroleum hydrocarbon (TPH) concentrations were also measured throughout the study to determine the effectiveness of the treatments.

Results: The amended soils showed greater reductions in TPH concentrations than the untreated control. The 25% contaminated soil plus compost treatment recorded the lowest final TPH concentration of 128.10 ± 10.09 mg/kg, while the 25% contaminated soil plus NPK treatment recorded 182.00 ± 25.06 mg/kg at Week 9. Other amended treatments also showed considerable reductions, whereas TPH concentrations remained relatively high in the control. Soil pH gradually increased towards neutral or slightly alkaline conditions, while electrical conductivity rose sharply by Week 3. Nitrate concentrations generally increased across treatments, suggesting changes in nutrient availability that may have supported microbial activity.

Conclusion: The findings show that composted agricultural waste and NPK fertiliser can improve the remediation of hydrocarbon-contaminated soils, with compost alone producing the best result among the reported treatments. This approach offers a potentially affordable and environmentally friendly means of restoring contaminated land. Further research is needed to assess its long-term effectiveness under field conditions.